import java.util.Scanner;

public class P14_HoursAndMins {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int hours = Integer.parseInt(sc.nextLine());
        int mins = Integer.parseInt(sc.nextLine());

        int total = hours * 60 + mins + 15;

        int leftHours = total / 60;
        int leftMins = total % 60;

        if  (leftHours == 24) {
            leftHours = 0;
        }

        if (leftMins <= 9){
            System.out.printf("%d:0%d",leftHours,leftMins);
        } else {
            System.out.printf("%d:%d",leftHours,leftMins);
        }
    }

}